Oguzhan Atay - 31 Dec 2025 SCHEDULE 13G Report for BillionToOne, Inc. Class A common stock, par value $0.00001 per share (BLLN)

Filing Manager: Oguzhan Atay
Reporting Manager: Oguzhan Atay
Security: BillionToOne, Inc. Class A common stock, par value $0.00001 per share
Symbol: BLLN
Shares outstanding: 43,929,603 shares
Disclosed Ownership: 3,206,861 shares
Ownership: 7.3%
Form type: SCHEDULE 13G
Filing time: 17 Feb 2026, 17:00:01 UTC
Date of event: 31 Dec 2025
SEC: View on sec.gov

Reporting Managers (1)

Name	Ownership	Shares Owned	sole voting power	shared voting power	Signature	Title	CIK
Oguzhan Atay	7.3%	3,206,861	3,006,861	200,000	/s/ Thomas Lynch, Attorney-in-fact	Thomas Lynch, Attorney-in-fact